Old PC wont turn on

On older mtrbds, they had as do new mtrbds. a VRM circuit/board. Voltage Regulator Module= VRM

Older mtrbds. tend to weardown this module as it was used to keep voltages within ceratin stable levels and cleanly, if it got outside the parmeteres or failed, the system failed. It maybe a smal upright bd. attached to mtrbd. or the area with alot of caps. present. Look for bulging or blown caps or leaking ones or severe discolration. If present, try a repair, but for this old system money&time spent better on new system. You can try a minized system plus any other ram(1 stick/bank) and no need for HDs, FDs, CD attached, verify so in bios, and try to boot, also yet another 3rd p/s unit or at least 350W. If it fails, either a bad componet on mtrbd. or device. These AMD cpus were very demanding ones at thier time it could have fried(nano secs), check under socket if discolored or glazing has occurred or sensor if present is good. These are areas to look into.

Feliz Navidad -----Willy

The IDE cables are off by row, pin or upside down or some lose nut, bolt, screw or a card came out of its socket...

Bob

I had an asus k7v. You might have a hardware problem. Does the mobo have an LED (like a k7v) that lights whenever the PS is plugged into the wall outlet? If the LED is out you have no power to the mobo. Because the PS powers up for a moment and then shuts down, you might have a short someplace. Unplug the drives, etc. from the PS. Unplug everything from the mobo but the CPU, ram, videocard, monitor, and power, and then boot up. Don't run the CPU without a fan. If the system boots, then shut down and unplug from the wall outlet and add the keyboard and reboot. Look for that LED, if it is lit then you still have power to the mobo. Don't add anything if it is still powered up. Keep adding components, one at a time, and rebooting until you find your problem. Keep trying and you will find the problem.
GP

I disconnected all the drives. The mouse, keyboard, printer cables. Removed the soundcard and network card. I disconected the case fans. (The network card had its standby power light on). I pressed the power and it started. I replaced each thing 1 by 1 and it still starts. So i don't know exactly what it was but it works now.